Method and apparatus for deodorizing oils



A. E. BAILEY METHOD AND APPARATUS FOR DEODORIZING OILS 4 Sheets-Sheet 1Oct. 12, 1954 Filed Oct. 16, 1948 Suventor WRIT/hi7 Oct. 12, 1954 A. E.BAILEY 2,691,665

METHOD AND APPARATUS FOR DEODORIZING OILS Filed Oct. 16, 1943 4Sheets-Sheet 2 ISnuentor Oct. 12, 1954 A. E. BAILEY 2,691,655

METHOD AND APPARATUS FOR DEODORIZING OILS Filed Oct. 16, 1948 4Sheets-Sheet I5 Snnentor Oct. 12, 1954 A. E. BAILEY 2,691,665

METHOD AND APPARATUS FOR DEODORIZING OILS Filed Oct. 16, 1948 4Sheets-Sheet 4 I I l L l l l I I l i l Inventor v attorney 5 PatentedOct. 12, 1954 METHOD AND APPARATUS FOR DEODIORIZING OILS Alton E.Bailey, Louisville, Ky., assignor, by mesne assignments, to NationalCylinder Gas Company, Chicago, 111., a corporation of DelawareApplication October 16, 1948, Serial No. 54,967 19 Claims. (01. 260-428)This invention relates to treatment of fatty oils and fats. Morespecifically, the invention is concerned with novel equipment and alsowith a novel method for effecting deodorization of fatty oils and fats.

The invention is of especial importance in connection with the treatmentof oils and fats to be employed in edible food products. It is highlydesirable in the case of such edible products that the oil or fatemployed be substantially free of objectionable odors.

With the foregoing in mind, it is a general object or purpose of theinvention to increase the effectiveness of deodorization and therebyimprove the quality of oils and fats to be employed in food products.

The invention is applicable to. quite a wide variety of oils and fats,for instance cotton seed oil, soya bean oil, and lard. Various of suchmaterials are commonly used in the preparation of food products such assalad dressing, margarine, etc.

Fatty oils and fats behave similarly with respect to deodorizationtreatment. The fats and oils are esters having certain chemicalsimilarities which need not be considered in detail herein and,moreover, the fats, though more or lesssolid at room temperature areoily liquids at the temperatures employed for deodorization. Forconvem'ence all such materials are herein referred to as oils or fattyoils.

It is well known that various of these oils in their more or less crudestate contain small percentages of certain constituents which impart tothe oil an objectionable odor; and a number of processes have beendeveloped for effecting deodorization of such oils.

In the deodorization techniques already known, it has been common toutilize heat, reduced pressure and stripping steam. In a typical priortreatment a batch of oil is heated in a simple tank having a vacuumconnection at the top, while introducing stripping steam into the bodyof the oil.

An important object of the present invention is to greatly increase theefficiency of the stripping action of the steam, as compared with priortechniques.

A further object of the invention is to increase the efliciency of thetreatment with reference to drawing the vacuum desirably established inthe treament equipment.

A further object of the invention relates to improvements in thestructure of deodorization equipment.

The above and many other objects and advantages can best be understoodfollowing a description of the equipment used and further reference istherefore made herebelow to such objects and advantages.

The drawings illustrate a preferred form of equipment and in thesedrawings Figure 1 is a schematic View of an oil deodorization systemconstructed according to the present invention;

Figure 2 is a vertical sectional view of a treatment columnincorporating improvements of the invention;

Figure 3 is an enlarged plan view of certain baffles used in associationwith oil treatment trays according to the invention, this view beingtaken as indicated by the line 33 on Figure 4.

Figure 4 is a vertical sectional view taken as indicated by the line 4-4on Figure 3, illustrating the upper portion of an oil treatment trayand. baffles associated therewith;

Figure 5 is a fragmentary horizontal sectional view through a part ofthe shell of the treatment column shown in Figure 2, showing certainparts in plan outline; and

Figure v6 is a fragmentary view taken as indicated by the line 66 onFigure 5.

In accordance with the present invention, the oil to be treated issuccessively delivered to a series of treatment zones defined bysuperimposed trays mounted within the treatment column. A given batch ofoil is retained in each treatment zonefor a predetermined time intervaland is thereafter delivered to the next treatment zone where it is againretained for the same time interval. Following the treatment in thesecond zone the batch is delivered to a third treatment zone, and soforth, throughout the series. In addition, as soon as one batch has beendischarged from the first treatment zone, a new batch is introduced intothe first zone, so that all zones of treatment are in concurrentoperation,

the batch in each zone being of the same size and being treated for thesame period of time. In the preferred form of equipment, as fullydescribed herebelow, there are five treatment zones through which eachbatch of oil is delivered, the respective treatments effected in each ofthese five zones being: first, heating of the oil to a temperature beloweffective deodorization temperature, with accompanying deaeration of theoil; second, further heating of the oil to effective deodorizationtemperature; third, deodorization by steam stripping; fourth,deodorization by steam stripping; and fifth, cooling.

With the foregoing brief description in mind, attention is now directedto the schematic view of Figure 1. As there seen oil is delivered from asupply A to a measuring tank B and from there to the several zones oftreatment within the treatment column C. From the bottom of the columnthe oil is discharged-into a drop tank-or storage vessel D. If desired,the oil may thenbe delivered to a point of use through a filter E.

Reduced pressure is maintained within the col-- umn C by means of asteam jet ejector System15 having a connection F with the columnC nearthe top thereof. The ejector system for pressure reduction within thecolumn C may be of: known type and the details thereof need not beconsidered herein.

The regions of the several treatment zones within the column C areindicated by the brackets numbered i to 5 inclusive, in Figure 1.Stripping steam is adapted to be introduced into each of the treatmentzones from asteam supplyconnection 6 having branches 1, 8, 9, l and.eX-- tended to perforated steam inlet pipes l2," I3, 14,. I and iii.Zone I has-heatercoils ll thereinv adapted to be heated by circulationofsteam therethrough. Similarly,-each of zones 2 and l is providedwith'heater coils; as shown at andv 2i. These-heater coils are-adaptedto the circulation of a heat exchange medium, for instance the vapor ofa eutectic mixture of diplienyl and diplienyl oxide. This heating vapormay be supplied fromtheboiler G through a supply con.- nection 22 havingbranches 23 and 26,: the medium being returned to the boiler throughpipes 25 and 26 and the return line 21.

Zone 5 is providedwith a cooling coil 28 through which a cooling medium,such as water, may be. circulated.

Condensate may bedrained'from the shell of columnC through a valvedrainage connection 3 l. delivering into a drainage tank 32.

Figures 2 to 5 illustrate various features of construction of the columnC shown in Figure 1. This column comprises ashell 33 preferably ofcylindricalform arranged with its axis vertically disposed. The columnis closed at the top by'a head member 34 and at the bottom the column.has a downwardly dished closure-wall 35 with which the drainage pipe 3!is associated.

The'several zones of treatment withinthe column are defined byvertically superimposed traysindicated by arrows numbered Itot-inclusive,- corresponding to the numbering of the zones in Figure 1.These trays are all of similar construc-. tion and a full detaileddescription of each one will therefore-be unnecessary. Consider for ex--ample the top tray, which appears in Figures-2, 3 and 4. This trayhasabottom wall 36 and four upright side walls 31, thereby forming a squaretray as clearly appears in Figure 3." The sidewalls of this trayarespaced appreciably from the shell wall and the angled corners thereofproject ,to. points closely adjacent to theshellwall to receive supportfrom bracketssuch asindicated in Figure 5 at 38.

Toward the topof the tray a system of baffles is provided, thesebeingbest shown in Figures 3 and4. As there seena multiplicity of baffleplatesl8 and i9 are assembled inthe pattern of open squares nested onewithin another, beinginterconnected in spaced relationship by spacedangle pieces 29,, to provide a tortuous pathfor the.es cape of vaporsfrom thetray. The .bafile plates. are further braced bystraps 39 securedto .the side walls of the tray and also to the center piece a to whichthe innermost of the baflie plates Illa are secured. The outermost ofthe plates I8 are connected with the side walls of the tray by plates19a. Plates I812 at the side walls of the tray complete the bafiiesystem. In addition to the function of providing a tortuous path forescape of vapors from. the tray,the bafiie system further constitutes anefiective means for breaking up or splattering the oil which is thrownupwardly against the bafiies in the manner described herebelow, while atthe same time preventing escape of oil particles from the tray. Thesplattering of the oil is of importance in enhancing the strippingemciency of the steam, as will further appear.

Above the baffle system is a peaked hood 3 9 carryingv a dependingsquare skirt 40 projectin downto a level somewhat below the top edges ofthe tray walls 37 and cooperating therewith and also with the baflleplates [8b to define a tortuous exit passage for vapors leaving the trayinto-:the shell spacesurrounding the trays:. In eifect, the: plates l8b(which project inwardly fromthesidee walls of the tray) form a deflectorringunderlying the skirt 40, which depends from thehood.39.-; Drainageports are preferably provided through the plates lflb near-the outeredges thereof for: returnof small amounts of oil which. may work. theirway to the region above the plates I811. The hood 39 is supportedbystraps M and. the edges of the hood advantageously project somewhatbeyond the side-walls of the tray so that any condensate which may dripfrom the edge of the hood will be delivered into the-shell space, ratherthan-into the interior of the tray.

A depressed corner portion 42 is provided at one top corner of eachtray, being walled off from the baffle system, and this portion isaperturedto pass, the oil-inlet pipes for the several trays. Thus, forthe toptraythe oil inlet pipe 43 (receiv-- ing oil from the measuringtank B) extends into the toptray through the peaked hood 39 and thecorner portion 42; A typical batch of oil will be ofa size to fill thetray to the level indicated at L;

A drop or, discharge valve 46 communicateswith the bottom of tray 1 andprovides for delivery oi the batchof ,oil therefrom downwardlyinto tray2 through the delivery pipe 47; Trays 2 to 5 inclusive are ofessentially the same construction as that fully described above,eachtray having bottom and side walls, hood andbaflle's, as is shown inFigure 2.. Delivery of oil from'tray 2.to tray 3 is effected by valveand discharge pipe 49. Valve 50 and pipe 51 serve to deliveroil fromtray 3 to -tray.4. Oil isdelivered from tray 4 to tray 5 by valve '52and discharge pipe- 53. At the bottom of tray 5 a discharge valve '54"is provided which controls the flow into the final discharge pipe 55extending downwardly througha connection 56 passing through the bottom'35 of the shell. Pipe 55 serves to discharge the oil from tray 5 intothe drop tank D (see Figure 1). Connection 56 with the drop tankprovides for-communication between the .vacuum space of the shell andthe drop tank Dto thereby efiect'reduction of pressure in the drop tank.

Shell C'is provided with a'series'ofmanholes-'- each of which islocated-adjacent one -of-*the* valves 46,18; 50,"52:and 54. The manholesare provided with covers 51, 58 5 9, Hand H which- ,1 between thevertically superimposed trays.

Further features of the tray arrangement inthe shell and of thearrangement of the drop valves between trays is shown in Figures and 6.The general arrangement of parts is similar so that not all of them needbe described. The showing of Figure 5 illustrates in plan the top oftray 2 and the drop valve 46 between tray 1 and tray 2. This figureshows that an appreciable space is provided within the shell around thetrays. Figures 5 and 6 further show drop valve operating mechanismincluding flexibly jointed shafting 44 penetrating the shell wall 33 andconnected with a valve operating motor 45 which may be mounted on theoutside of the shell.

In a typical installation and operation thereof each tray has an oilcapacity of 2500 pounds. A measured 2500 pound batch of oil, forinstance cotton seed oil, is introduced from the measuring tank B intotray I. The batch is held in tray I for a period of one-half hour,during which time it is heated by the coils 11 and is subjected'to thestripping action of steam introduced through the perforated pipe l2. Thesteam ejector is of course placed in operation prior to introduction ofany oil into the column and a low pressure is established within thecolumn, for instance a pressure of 6 mm. Hg. Each tray is placed incommunication with the vacuum zone ofthe shell through the baffledpassages at the top, so that the reduced pressure is effective withreference to the interior of all trays.

In the typical treatment, the temperature is raised in tray l to about320 F. Incidental to this increase in the temperature of the oil partway to effective deodorization temperature, the oil is deaerated, theair passing off with the stripping steam'into the vacuum zone in theshell and finally out through the vacuum connection F. At the conclusionof the half-hour treatment in tray l, the batch of oil is delivered totray 2 and is retained in tray 2 for an additional onehalf hour periodduring which time it is subjected to the action of stripping steam, andthe temperature is raised by the heater coil 20 to an appropriate valuefor deod'crization, for instance 460 F. During this second one-half hourperiod, another batch is introduced into tray l and is treated as abovedescribed to increase the temperature of the oil to a point beloweffective 'deodorization temperature and to effect deaeration.

Following the second one-half hour period the batch in tray 2 isdelivered to tray 3 and is held therein for a third treatment period ofone-half hour, during which time deodorization is effected under theinfiuence of stripping steam introduced through the perforated pipe l4.The drop valves are then again operated to effect delivery of the batchfrom tray 3 to tray 4, and to advance the batches in trays I and 2. Intray 4 the batch is retained for a fourth period of one-half hour,during which time it is further heated by the heater coil 2| so as tomaintain this batch at an effective deodorization temperature. Strippingsteam is also here introduced through the perforated pipe l5, andfurther deodorization takes place.

At the conclusion of the fourth one-half hour period the drop valves areoperated to deliver the batch from tray 4 to tray 5, and also to advancethe following batches. In tray 5 the batch is again retained for aperiod of one-half hour during which time it is subjected to the actionof stripping steam introduced through pipes l6 and also the coolingaction of the cooler coil 28. This cooling coil is adapted to drop thetemperature of the oil to about F., so that upon discharge of the oilfollowing the fifth one-half hour treat.- ment period, the oil is at atemperature well below that at which any appreciable oxidation wouldoccur. Upon discharge of the batch from tray 5 it mingles with the oilin the tank D and will be pumped therefrom to the filter E.

From the foregoing it will be seen that the sequence of treatmentsprovided constitutes in ef feet a semi-continuous treatment, all phasesof which are occurring concurrently, each batch of the oil beingsequentially advanced through each treatment zone.

While the foregoing constitutes the description of the preferred form ofmy invention, it will be understood that various other arrangements ofthetrays may be used. Ordinarily it will be advantageous to employ twoheating trays as described above, wherein the oil is heated with steamand thereafter with diphenyl and diphenyl oxide vapor, or other hightemperature heating medium, as thereby the size and cost of the boilerfor high temperature heatin is minimized. However, alternatively,heating to effective deodoriz- 'ing temperature may be effected whollyby means of the high temperature medium, without the use of heatingsteam, in one or more heating trays. Similarly, in some cases one of thedeodorizing trays may be eliminated, although ordinarily optimumdimensions in the apparatus will be achieved with two trays. In thefive-tray arrangement, the heater coils in tray 4 may not al- Ways berequired, or, in some cases, it may be advantageous to provide heatingcoils in both trays 3 and 4. The preferred arrangement of heating coilsin trays 3 and 4 will be dictated primarily by the temperatures requiredfor different portions of the deodorization period;

The distribution of stripping steam to the different trays is notcritical and good results may be obtained with a wide variety ofsteaming rates, provided that sufiicient steam is injected into thedeodorizing trays to provide the required removal of volatileodoriferous materials. However, for reasons of economy, it is preferableto inject the greater part of the total stripping steam into thedeodorizing trays, providing the heating and cooling trays with onlyenough stripping steam to effectively deaerate the fresh oil and toagitate the oil sufiiciently to give good heat transfer from the heatingor cooling coils. For example, in the typical apparatus described in theforegoing, with a capacity of 5000 pounds of oil per hour, '75 poundsper hour of stripping steam may be injected into each of the deodorizingtrays 3 and 4, as compared with 25 pounds per hour injected into each ofthe heating trays l and 2 and the cooling tray 5.

It will be understood that the temperatures employed in the severalstages of treatment'will necessarily vary according to the particularoil being treated and according to other factors, such as the degree ofdeodorization treatment necessary to substantially eliminateobjectionable odors.

In considering various of the objects and advantages of the system asabove described, attention is first called to the fact that vaporizationor stripping efficiency is a factor of prime importance in the operationof any deodorization equipment or process. When the stripping steamisintroduced into a body of oil under reduced pressure the steam bubblesexpand and apparently absorb the constituents or odor bodies which it isdesired to remove. When the steam is carried "away; such constituents:are married ..Withl.it..

Eflicient :operationv therefore requires bringing all: partswofl :the.mass l of :the oil. into ..contact with: the strippin steamasirapidlyand thoroughly. as.

possible;

The equipment of the present invention is ,out-xstanding with referenceto stripping efliciency. Thissisiduein large part to: the, employment,of thesbafile. or splash plates 18,119, etc., which are located: abovebut relatively; close to the surface Ofzthb=i1ill each'ofthe trays. Thekinetic energy-'- otithe rapidly expanding bubbles of steam risingthrough the batch in each tray acts tolift. masses of:v :the {011. and;to 1 violently splash 1 the oil against the b'afiles, with: the result.that'theoil is'eff'ectivelysplattered in relatively fine drops ormasses, thereby greatlyenhancing the-access-of the stripe ping steam-.toall parts of the oilinthe, tray.

It :will be-observed that the-baffles are so are ranged-'atthetop ofeach tray thatonly very:

small. quantitiesof the oilz'are carried above the bafllesduringtreatment. The'hood 39.-andskirt arranged over the'top of each traypresent-a surface for catching and returning to the tray the smallquantities of oil-which escape through the bafli'es; Moreover, both thebaflles andjtheskirt.

400(cooperating with the side walls'of the tray) serve :to definetortuous passages which prevents oili'iromiescaping from-the traynotwithstanding the violent splashing of the oil against the baflles.

The hoodw just mentioned also acts'to prevent any volatile materialsdistilledfrom the oil which" condense upon the :shell or otherrelatively cold portions of the apparatus, from-running. back into theoiL being deodorized. Any such condensate willaultimately draindownward-within th shell and accumulate in thebottom of the shell, fromwhich it may be withdrawn through the drainage pipe-3l:.

Asa consequence-of the efiicient stripping ob tained by splashing ofoil-against the baflle plates.

and theefiective prevention of reflux of distilled materialback into theoil, it has been found'that thesteam. required for stripping is greatlyreduced as compared with the well knownbatch deodorizer of the priorart. For example, only'4.5 pounds of stripping-steam per 100 pounds ofoil deodorized are requiredfor many edible fat prod ucts, includinghydrogenated cottonseed .and soy bean oils, ascompared with about25pounds ordinarily used in batchdeodorization.

Since the 'oil' treatment zones are substantially completely isolatedwithin the trays and outof contact with the-structure of the shell, itispossible'to fabricate the shell of steelyevenordinary carbonsteel,without adversely; ailectingthe oil being. treated. According to :theinvention, thev trays, bafiles and associated parts coming-moon tact-2'with the oil are preferably.- fabricatedof nickelor aluminum, since-ithas. been found thatv these two-metals are substantiallyinert with reference to their pro-oxidative effect on iatty oils and fats underdeodorization conditions. In prior attempts to avoid adverse influenceof metal-to,-- oil contact in deodorization equipment, itv has.

been proposed to .fabricate a treatment tank or shell of a metalsuch asnickel orsaluminum for, theareason that insuch prior equipmentthe-arrangement of. the treatment zone-or zones was such as to bring theoilintocontactwith theshell, either, at the-side walls of. the. shellore-by virtue of refluxing from the top of the. shell or both; Thisproposal, however, would resultiri a. very expensive shell structure,particularly in View of the fact that a highvacuum must be main tainedwithintthewshell. *1 An: important -featureof: the presentinvention,therefore, is the-rabricae 1 tilonuofuthe shellof aninexpensiv and strong. metal-rsuch as carbon steel; andthe fabricationof the=trays and associated parts of nickel or alumi'-- numgthephysicalarrangement of the trays, baffles,: etc.-, being suchas tosubstantially eliminate contact of the oil-being treated with any partof theshell structure... Fabrication of the trays from-.m'ckeloraluminum is not excessively, costlyparti'cular-ly since :thetrays need not withstand a: largemressure difierential and therefore maybe made of thin gauge-sheeting.

Still another .feature of great importance is the employmentottrayshaving side wallsspaced appreciably from the-insidewalloi theshell. This provides a vacuum .spacesurrounding the trays and. extendingthroughout the height of the In the first place,- the,

the height ofthe .column, together with the particular. arrangement oftrays provides independent communication of each tray with the vacuumspace and thereby reduces pressure-losses which. would. otherwise occurwere the vacuum drawn serially through the oil in the several treatmentzones. In this, way, substantially the same lowyacuumis maintained onthe oil throughout the treatment period.

Aiurther desirable feature of the vacuum space between the trays andtheshellis that this method.of construction renders it. impossible forair; leaking accidentally into the shell, to pass through theoilinprocess of deodorization, It is well known that air leaking, into. thedeodorizer and reacting with the hot oil therein, is a prime cause oftrouble invth'e, operation of batch deodorizers. or. oth'erdeodorizersof conventional.construction.

Itwillbe observed that the vacuum space surrounding. the trays is.provided by employment of trays .whichare square, rather than circularin horizontal.section. This is of advantage for several. reasonsincluding the fact that the square or'angular tray construction greatlysim-. plifies the fabrication of the trays, bailies, etc. Moreovenwiththe trays andshell proportioned inthe manner clearlyappearing in Figures3 and 5, thecornersof the traysextendto positions adjacent the shellwall. and this simplifies the problem of mounting the, trays within theshell.

Still another advantage oithe equipment disclosed'is that a change inthe stock of oil beingtrleated need not necessarilyresult inintermixing'of one. stock Withanothen. This is avoidedsincethegoilistreatedin batches which are advanced through successivetreatment zones in amanner .to handle such batches completelyindependently of each other, so that a change in the oilbe ing treatedmaveven be effected without interrupting the operation of the column.All that is required for this purpose is that when the lastbatch'cf onestock has been discharged from the lasttreatr'nent zone, the first batchof.

thefdifierent 'oil'be divertedto a separate storage or drop 'tankafterit' has been subjected to thetreatment in the last treatment zone.

In .operating-the equipment disclosed herein, it. is preferred .toestablisha pressure in the column atleastasldw-aslO1mm. Hg; In zones 1and2 it is preferred to heat the oil at such a rate that upon leavingzone 2 the oil is at a temperature between 400 F. and 500 F. After theslight temperature drop which may occur in zone 3, the temperature ispreferably brought back again to the desired temperature in the rangebetween 400 F. and 500 F. by the heater in zone 4. The cooling in zonepreferably effects a temperature drop to a point below 150 F.

Because of the fact that the oil is preliminarily deaerated in zone 1and further because of the fact that the oil is treated in all zoneswithout coming in contact with metals which would adversely influencethe oil, it is practicable to effect deodorization (principally in zones3 and 4) at relatively high and therefore very effective deodorizationtemperatures. More rapid deodorization is therefore achieved.

In considering the nature of the treatment which occurs in each of theseveral zones, it should be noted that as the temperature approachesdeodorization temperature in zone 2, some preliminary deodorization willalso take place.

The processing of oil in the equipment herein disclosed will also serveto remove free fatty acids from the oil being treated, this being ofgreat importance, particularly where the treated oil consists of a fat,such as lard, which does not require alkali refining to remove pigmentsor other impurities.

I claim:

1. Equipment for use in deodorizing fatty oils and fats comprising ashell having a vacuum connection, a series of vertically superimposedtrays in the shell including a first or upper tray, a second orintermediate tray and a third or lower tray, normally closed connectionsfrom tray to tray having discharge valves providing for sequentialdelivery of a batch of oil introduced into the uppermost tray downwardlyfrom tray to tray, each tray having communication with the vacuum spacein the shell independently of other trays, a heater for a batch of oilin the first tray providing for heating of such batch to a temperatureappreciably below deodorizing temperature, a heater for a batch of oilin the second tray providing for heating of such batch to deodorizingtemperature, and an inlet for introducing stripping steam into a batchof oil in the third tray to effect appreciable deodorization of suchbatch in the lower tray.

2. A construction according to claim 1 and further including a fourthtray in the shell below said third tray, a cooler for cooling a batch ofoil in the fourth tray, and a normally closed connection having adischarge valve for delivering a batch of deodorized oil from the thirdtray to the fourth tray,

3. A construction according to claim 1 and further including a fourthtray in the shell below said third tray also in communication with thevacuum space in the shell, a normally closed conne tion having adischarge valve for delivering a batch of oil from the third tray to thefourth tray, an inlet for introducing stripping steam into a batch ofoil in the fourth tray to effect further deodorization of such batch inthe fourth tray, and a heater in at least one of the third and fourthtrays for maintaining deodorization temperature of the oil therein.

4. A construction according to claim 3 and further including a fifthtray in the shell below said fourth tray, a cooler for cooling a batchof oil in the fifth tray, and a normally closed con- 10 nection having adischarge valve, for delivering a batch of deodorized oil from thefourth tray to the fifth tray.

5. A construction in accordance with claim 1 and further including afourth tray in the shell below said third tray also in communicationwith the vacuum. space in the shell, a normally closed connection havinga discharge valve for delivering a batch of oil from the third tray tothe fourth tray, an inlet for introducing stripping steam into a batchof oil in the fourth tray to effect further deodorization of such batchin the fourth tray, a fifth tray in the shell below said fourth tray, acooler for cooling a batch of oil in the fifth tray, and a normallyclosed connection having a discharge valve, for delivering a batch ofdeodorized oil from the fourth tray to the fifth tray.

6. Equipment for use in deodorizing fatty oils and fats comprising ashell having a vacuum connection, a series of vertically superimposedtrays in the shell, including an upper tray, an intermediate tray and alower tray, normally closed connections from tray to tray havingdischarge valves providing for sequential delivery of oil from each trayto the next lower tray in the series, each tray having communicationwith the vacuum space in the shell independently of the other trays, aheater for a batch of oil in said upper tray providing for heating suchbatch to deodorizing temperature, a heater for a batch of oil in saidintermediate tray providing for maintaining a batch of oil atdeodorizing temperature, and a cooler for a batch of oil in said lowertray, each of said trays being provided with an inlet for introducingsteam into the oil in said tray.

7. Equipment for use in deodorizing fatty oils and fats comprising ashell of circular horizontal section, a seriesof vertically superimposedtrays in the shell each being of angular horizontal section and havingsuperimposed angular corners adjacent the shell wall, oil dischargeconnections extended from tray to tray in said superimposed angularcorners, valves in said connections, valve operating means providing forserial delivery of a batch of oil from tray to tray and normally closedaccess ports in the shell wall adjacent said connections.

8. Equipment for use in deodorizing fatty oils and fats, comprising aseries of trays for the oil to be treated, a shell surrounding the traysin spaced relation thereto to provide shell space between the shell walland the trays, in which construction any air leakage from the exteriorof the shell to the interior thereof enters the shell space between theshell wall and the trays, the upper portion of each tray being open tothe shell space to provide for the discharge of vapors therefrom intothe shell space, and the shell having an offtake connection forevacuating the shell space and for withdrawing vapors and leakage airout of the shell space without contact with the oil in the trays, andsteam supply means for introducing steam into the oil in at leastcertain trays of said series including a separate steam inlet in eachsuch tray for the introduction of fresh steam into the oil in each suchtray independently of the introduction of steam into other of such traysand without contamination with vapors withdrawn from other trays or withleakage air in the shell space.

9. A process for deodorizing fatty oils and fats in a treating columncomprising a plurality of trays for the oil to be treated, and a shellsurrounding the trays in spaced relation toprovide 1 l shell spacebetween the shell wall and the trays, the upper portion of each traybeing open to the shell space to provide for the discharge of vaporstherefrom into the shell space, in which construction any air leakagefrom the exterior of the shell to the interior thereof enters the shellspace between the shell wall and the trays, which process comprisesheating the oil in certain of said trays, introducing fresh steam intothe oil in each of said trays, and withdrawing the vapors from each traythrough the shell space and discharging all of the withdrawn vapors,together with any leakage air, externally of the shell without recontactof said withdrawn vapors or contact of said air with the oil in any ofthe trays.

10. Equipment for use in deodorizing fatty oils and fats, comprising aplurality of vertically superimposed trays for the oil to be treated, ashell surrounding the trays in spaced relation thereto to provide shellspace between the shell wall and the trays, each tray being upwardlyopen for discharge of vapors therefrom into the shell space, and eachtray being provided with a normally closed oil discharge connection theinlet end of which communicates with the interior of the tray throughthe bottom thereof to provide for substantially complete discharge ofall of the oil in the tray, the discharge connection for an upper traybeing extended to deliver the oil therefrom to the next subjacent trayand the discharge connection for the lowermost tray being extended outof the shell, and the discharge connections having discharge valvesproviding for sequential delivery of a batch of oil initially introducedinto the uppermost tray downwardly from one tray to another.

11. Equipment for use in deodorizing fatty oils and fats comprising ashell having a vacuum connection, a series of at least three trays inthe shell each having side walls spaced from the shell wall to provide avacuum zone at least in large part surrounding the trays, at least thesecond and third of said trays being provided with stripping steaminlets, each tray being upwardly open for discharge of vapors therefrominto the shell space, a heater in the first tray of said series forraising the temperature of the oil to effective deodorizationtemperature, an oil discharge connection for delivering a batch of oilfrom the first tray to the second tray and having its inlet endcommunicating with the interior of the first tray through the bottomthereof to provide for substantially complete discharge of all of theoil in the tray, a similarly arranged oil discharge connection extendedbetween the second tray and the third tray, normally closed valves insaid discharge connections, and valve operating means providing forserial delivery of a batch of heated oil from the first tray to thesecond tray for deodorization therein and thereafter from the secondtray to the third tray for further deodorization therein.

12. Equipment for use in deodorizing fatty oils and fats comprising ashell of circular horizontal section having a vacuum connection, aseries of vertically superimposed trays in the shell, each tray being ofangular horizontal section with side walls spaced appreciably from theshell wall to provide a vacuum zone in the shell at least in large partsurrounding the tray, each tray also having a normally closed connectionin the bottom thereof providing for sequential delivery of oil from trayto tray, the angular corners of all the trays lying adjacent the shellwall, and tray supporting devices located at said corners and 12connected with the shell for support of the trays within the shell.

13. Equipment for use in deodorizing fatty oils and fats comprising ashell defining a closed chamber and having a vacuum outlet connectionfor removing vapors from said chamber, a series of trays mounted withinsaid chamber, each tray being adapted to contain a body of oil andhaving an outlet for vapors released from said body of oil, said traysalso being spaced from said shell to provide a common vacuum spacewithin the chamber for receiving vapors directly from the vapor outletsof all of said trays, a normally closed oil discharge connection for thelast tray of said series extended outside said shell, normally closedoil discharge connections providing for gravity delivery of oil fromeach of the other trays in the series to the next tray in the series,and discharge valves in all of said discharge connections operable toprovide for sequential delivery of a batch of oil, initially introducedinto the first tray, from tray to tray in the series.

14. Equipment according to claim 13 and further comprising oil heatingmeans including a heater in one tray connected to a source of relativelylow temperature heating fluid and a heater in another tray connected toa source of relatively high temperature heating fluid, said heatersbeing operable to heat simultaneously batches of oil in said two trays.

15. Equipment for use in deodorizing fatty oils and fats comprising ashell defining a chamber and having a vacuum connection for the removalof vapors from said chamber, tray structure mounted within said chamberand having. side walls spaced from, said shell to define therewith avapor space at least in large part surrounding said tray structure, saidside walls also defining a tray space adapted to contain a body of oil,means for introducing gaseous medium into the body of oil in said traystructure below the surface of the oil, and fluid deflecting structureoverlying said body of oil and operative to intercept drippingcondensate and to deflect such condensate laterally of the traystructure into said surrounding vapor space, said tray space being incommunication with said surrounding vapor space at an elevation abovethe level of said body of oil but below said deflecting structure toprovide for flow of vapors from the tray space into the surroundingvapor space.

16. A construction according to claim 15 in which the condensatedeflecting structure comprises a hood spaced above the tray structureand extended laterally beyond the side walls thereof.

17. A construction according to claim 15 and further including vapordeflecting means below the condensate deflecting structure defining atortuous passage in the path of flow of vapors from the body of oil inthe tray structure to the region of communication with the surroundingvapor space in the shell.

18. Equipment according to claim 15 and further including means in theregion of vapor flow from the tray space into the surrounding vaporspace providing a tortuous vapor flow path and comprising a vapordeflecting element extending downwardly from the region of thecondensate deflecting structure, and a cooperating element projectinginwardly from the region of a side wall of the tray structure, saidelements being spaced and relatively positioned to cooperate inestablishing said tortuous flow path.

19. Equipment for use in deodorizing fatty oils 13 and fats comprising ashell having a vacuum connection, a series of oil treatment traystructures in the shell each having side walls spaced from the shellwall to provide shell space at least in large part surrounding the traystructures, means 5 for introducing gaseous medium into the oil in atleast one tray of the series, an oil supply connection penetrating theshell wall and providing for delivery of oil into the first tray of theseries, connections within the shell from one tray to another in theseries providing for gravity delivery of oil sequentially from tray totray in the series, and an oil discharge connection penetrating theshell wall and providing for discharge of the oil from the last tray ofthe series, the tray structures having means overlying the oil thereinand serving to intercept dripping condensate and to deflect suchcondensate laterally of the tray structures into the surrounding shellspace, and each tray structure having lateral communication with saidsurrounding shell space at an elevation between the level of oil in saidtray structure and the condensate deflection means to provide a lateralpath of discharge of References Cited in the file of this patent UNITEDSTATES PATENTS- Number Name Date 664,015 Denaeyer Dec. 18, 19001,296,013 Schlossstein March 4, 1919 1,543,853 Hunziker June 30, 19251,582,899 Cassidy May 4, 1926 1,605,265 Millard Nov. 2, 1926 1,638,451Nixon Aug. 9, 1927 1,920,623 Becker Aug. 1, 1933 2,048,179 Chandler July21, 1936 2,280,896 Dean Apr. 28, 1942 2,303,811 Badenhausen Dec. 1, 19422,422,185 Dean June 17, 1947 FOREIGN PATENTS Number Country Date 242,316Great Britain Nov. 9, 1925 277,085 Great Britain Sept. 7, 1927

1. EQUIPMENT FOR USE IN DEODORIZING FATTY OILS AND FACTS COMPRISINGSHELL HAVING A VACUUM CONNECTION, A SERIES OF VERTICALLY SUPERIMPOSEDTRAYS IN THE SHELL INCLUDING A FIRST OR UPPER TRAY, A SECOND ORINTERMEDIATE TRAY AND A THIRD OF LOWER TRAY, NORMALLY CLOSED CONNECTIONSFROM TRAY TO TRAY HAVING DISCHARGE VALVES PROVIDING FOR SEQUENTIALDELIVERY OF A BATCH OF OIL INTRODUCED INTO THE UPPERMOST TRAY DOWNWARDLYFROM TRAY TO TRAY, EACH TRAY HAVEING COMMUNICATION WITH THE VARUUM SPACEIN THE SHELL INDEPENDENTLY OF OTHER TRAYS, A HEATER FOR A BATCH OF OILIN THE FIRST TRAY PROVIDING FOR HEATING OF SUCH BATCH TO A TEMPERATUREAPPRICIABLY BELOW DEODORIZING TEMPERATURE, A HEATER FOR A BATCH OF OILIN THE SECOND TRAY PROVIDING FOR HEATING OF SUCH BATCH TO DEODORIZINGTEMPERATURE, AND AN INLET FOR INTRODUCING STRIPPING STEAM INTO A BATCHOF OIL IN THE THIRD TRAY TO EFFECT APPRICIABLE DEODORIZATION OF SUCHBATCH IN THE LOWER TRAY,
 9. A PROCESS FOR DEODORIZING FATTY OILS ANDFATS IN A TREATING COLUMN COMPRISING A PLURALITY OF TRAYS FOR THE OIL TOBE TREATED, AND S SHELL SURROUDNING THE TRAYS IN SPACED RELATION TOPROVIDE SHELL SPACE BETWEEN THE SHELL WALL AND THE TRAYS, THE UPPERPORTION OF EACH TRAY BEING OPEN TO THE SHELL SPACE TO PROVIDE FOR THEDISCHARGE OF VAPORS THEREFROM INTO THE SHELL SPACE, IN WHICHCONSTRUCTION ANY AIR LEAKAGE FROM THE EXTERIOR OF THE SHELL TO THEINTERIOR THEREOF ENTERS THE SHELL SPACE BETWEEN THE SHELL WALL AND THETRAYS, WHICH PROCESS COMPRISES HEATING THE OIL IN CERTAIN OF SAID TRAYS,INTRODUCING FRESH STEAM INTO THE OIL IN EACH TRAY THROUGH THE SHELLSPACE AND DISCHARGING ALL OF THE WITHDRAWN VAPORS, TOGETHER CHARGING ALLOF THE WITHDRAWN VAPORS, TOGETHER WITH ANY LEAKAGE AIR, EXTERNALLY OFTHE SHELL WITHOUT RECONTACT OF SAID WITHDRAWN VAPORS OR CONTACT OF SAIDAIR WITH THE OIL IN ANY OF THE TRAYS.